By his own majestic standards Messi, who missed nearly two months of the season through injury, has struggled to find his best form in recent weeks, while Barcelona have surrendered the leadership of La Liga to Real Madrid.

The Argentine superstar has scored 230 goals for the club since making his debut as 17-year-old a decade ago, but has looked ill at ease in recent weeks as he adjusts to the demands of manager Tata Martino’s tactics, leading to suggestions that he could be tempted to consider a new challenge in the summer.

But Xavi insists not even a world-record fee could tempt Barcelona into selling their star man.

“Of course there will always be stories about the best player in the world and in my opinion the best player ever - but Manchester City and any other team can forget about signing Messi,” Xavi told Goal.

“There is no transfer fee that could make it a good deal for Barcelona - and as everybody who knows him knows - he loves the club and has made it clear he never wants to leave.”

Barcelona head into the second leg of their Champions League last-16 tie against City with a healthy advantage after capitalising on Martin Demichelis’ red card and hold a 2-0 lead ahead of Wednesday’s return match at Camp Nou.

City were without Messi’s Argentina team-mate Sergio Aguero for the match at the Etihad Stadium a fortnight ago but the former Atletico Madrid striker is certain to start this evening and Xavi knows the tie is far from over.

He added: “It was a good result in Manchester - but we knew at the end of the game it wasn't over - and all the players know to expect a very tough 90 minutes.

“They have shown in England that they can score four or five goals in a game many times, so we have to respect their attacking talent and the ability of their players.

“We are confident we can progress, but must respect they are an excellent team and the job is not done.”